Lake Powell Water Supply Outlook, February 1, 2016

Note: This publication is scheduled for revision. If you have feedback on content, format, or publication frequency, please contact us.
Prepared by CBRFC
NOAA, National Weather Service
Colorado Basin River Forecast Center
Salt Lake City, Utah
www.cbrfc.noaa.gov

Contents

Lake Powell Sub-Basin Summaries




*Median of forecasts within each basin.





*Median of forecasts within each basin.







*Median of forecasts within each basin.




Upper Green Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Yampa/White Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Duchesne Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Lower Green Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Upper Colorado Mainstem Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Gunnison Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

Dolores Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.

San Juan Basin Conditions




Snow Water Equivalent in Percent of Median.
* Percent usable capacity, not percent average contents.
Click for multi-month Graph.


Upper Green Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Green
Daniel, Nr, Warren Bridge, At April-July138 173 205 84 225 275
Pine Ck
Fremont Lk, Abv April-July59 69 83 85 91 109
New Fork
Big Piney, Nr April-July145 205 255 72 300 405
Green
Fontenelle Res, Fontenelle Nr April-July325 445 515 71 610 805
Big Sandy
Farson, Nr April-July22 31 35 67 41 58
Green
Green River, Wy, Nr April-July305 450 515 71 615 845
Hams Fork
Frontier, Nr, Pole Ck, Blo April-July24 30 39 72 46 69
Viva Naughton Res April-July31 39 51 69 64 102
Blacks Fork
Robertson, Nr April-July50 63 75 84 89 114
Ef Smiths Fork
Stateline Res, Robertson,nr April-July17.7 19.6 23 88 28 33
Green
Flaming Gorge Res, Flaming Gorge Dam, At April-July420 580 685 70 830 1350


Yampa/White Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Yampa
Stagecoach Rsvr, Abv April-July18 21 25 109 28 38
Steamboat Springs April-July190 235 280 108 310 370
Elk
Milner, Nr April-July230 280 325 102 370 420
Elkhead Ck
Long Gulch, Abv, Hayden, Nr April-July44 59 70 96 80 92
Yampa
Maybell, Nr April-July620 740 910 97 1000 1200
Little Snake
Slater, Nr April-July89 117 135 87 159 189
Dixon, Nr April-July180 250 285 83 365 425
Lily, Nr April-July185 265 300 87 400 465
Yampa
Deerlodge Park April-July775 975 1200 97 1320 1600
White
Meeker, Nr April-July210 235 280 100 300 365
Watson, Nr April-July220 255 300 107 325 410


Duchesne Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Big Brush Ck
Vernal, Nr, Red Fleet Res, Abv April-July11.3 13.9 15.6 74 18.6 26
Ashley Ck
Vernal, Nr April-July24 32 37 74 41 63
West Fork Duchesne
Vat Diversion, Blo April-July7.8 10.2 11.7 63 13.5 19.1
Duchesne
Tabiona, Nr April-July58 70 80 74 90 110
Rock Ck
Upper Stillwater Res April-July48 55 63 85 71 94
South Fork Rock Ck
Docs Div, Blo April-July4.2 4.7 5.7 78 7 8.6
Rock Ck
Mountain Home, Nr April-July57 64 75 85 86 114
Currant Ck
Currant Ck Res April-July7 10.2 12.8 64 16.6 23
Strawberry
Solider Springs,nr April-July25 34 40 56 53 80
Starvation Res, Duchesne, Nr April-July49 66 75 67 91 135
Duchesne
Duchesne, Nr, Knight Div, Abv April-July119 143 153 79 174 215
Lake Fork
Moon Lake Res, Mtn Home, Nr April-July39 46 53 80 59 78
Yellowstone
Altonah, Nr April-July38 49 53 87 61 72
Whiterocks
Whiterocks, Nr April-July30 39 45 83 49 70
Uinta
Neola, Nr April-July42 55 63 85 68 95
Duchesne
Myton April-July150 210 230 70 285 390
Randlett, Nr April-July155 220 240 62 310 455


Lower Green Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
White
Blo Tabbyune Ck, Soldier Summit, Nr April-July7.1 10.9 13.7 88 17.1 22
Fish Ck
Scofield, Nr, Reservoir, Abv April-July17.5 22 24 80 28 39
Price
Scofield Res, Scofield, Nr April-July23 29 32 78 37 54
Green
Green River, Ut April-July1700 2110 2460 83 2900 4000
Huntington Ck
Electric Lake April-July5.4 7.7 9.7 73 12 18.6
Power Plant, Blo April-July22 28 33 83 40 58
Seeley Ck
Joes Vly Res, Orangeville, Nr April-July28 38 43 77 48 76
Ferron Ck
Ferron, Nr April-July22 30 34 89 38 55
Muddy Ck
Emery, Nr April-July12.9 16.4 18 90 22 31


Upper Colorado Mainstem Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Colorado
Lake Granby, Granby, Nr April-July135 160 190 86 220 290
Willow Ck
Willow Ck Res, Granby, Nr April-July30 43 48 102 58 88
Fraser
Winter Park April-July16 18 21 108 23 26
Williams Fork
Williams Fork Res, Parshall, Nr April-July65 85 94 98 102 132
Muddy Ck
Wolford Mountain Reservoir April-July32 45 57 106 65 80
Blue
Dillon Res April-July120 146 165 101 177 225
Green Mtn Res April-July192 235 280 102 300 380
Colorado
Kremmling, Nr April-July575 730 820 95 925 1200
Eagle
Gypsum, Blo April-July230 275 320 96 375 480
Colorado
Dotsero, Nr April-July950 1170 1340 96 1500 1920
Frying Pan
Ruedi Res, Basalt, Nr April-July95 113 140 101 150 195
Roaring Fork
Glenwood Springs April-July500 600 700 101 750 965
Colorado
Glenwood Springs, Blo April-July1470 1800 2060 98 2250 2900
Cameo, Nr April-July1670 2000 2300 97 2500 3300
Plateau Ck
Cameo, Nr April-July95 115 135 109 145 205
Colorado
Cisco, Nr April-July3500 4000 4500 101 4900 6700
Lake Powell, Glen Cyn Dam, At April-July5000 6000 6700 94 7500 10300


Gunnison Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Taylor
Taylor Park Res April-July65 85 94 95 111 130
Almont April-July105 131 145 94 166 200
East
Almont April-July110 139 160 88 180 225
Gunnison
Gunnison, Nr April-July230 295 330 89 385 475
Tomichi Ck
Gunnison April-July44 60 75 101 88 120
Lake Fork
Gateview April-July100 115 135 110 153 185
Gunnison
Blue Mesa Res April-July460 575 640 95 710 930
Morrow Point Res April-July520 635 700 95 770 990
Crystal Res April-July605 720 785 94 855 1080
Muddy Ck
Paonia Res, Bardine, Nr March-June75 88 96 100 112 145
April-July0 0 0 0 0 0
Nf Gunnison
Somerset, Nr April-July210 255 290 98 335 410
Surface Ck
Cedaredge April-July11 15 17 101 20 25
Uncompahgre
Ridgway Res April-July82 100 112 111 122 155
Colona April-July100 135 150 109 170 220
Delta April-July80 110 125 111 145 210
Gunnison
Grand Junction, Nr April-July1000 1270 1450 98 1700 2200


Dolores Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
Dolores
Dolores April-July215 265 300 122 345 410
Mcphee Res April-July250 320 365 124 415 500
San Miguel
Placerville, Nr April-July100 130 147 115 165 195
Dolores
Cisco, Nr April-July440 600 700 124 800 1000


San Juan Specific Site Forecasts (kaf)

Click site name for graph.
Forecast
Period		90%
Exceedance
Volume		70%
Exceedance
Volume		50%
Exceedance
Volume		Percent
Average		30%
Exceedance
Volume		10%
Exceedance
Volume
San Juan
Pagosa Springs April-July170 210 235 109 265 320
Carracas, Nr April-July280 335 390 103 450 550
Navajo Res, Archuleta, Nr April-July500 600 735 100 890 1080
Farmington April-July770 990 1120 102 1330 1640
Bluff, Nr April-July720 945 1100 100 1270 1570
Rio Blanco
Pagosa Springs, Nr, Blanco Dam, Blo April-July42 49 58 107 69 80
Navajo
Chromo, Nr, Oso Div Dam, Blo April-July48 57 68 105 79 94
Piedra
Arboles, Nr April-July160 185 230 110 265 320
Los Pinos
Vallecito Res, Bayfield, Nr April-July150 188 205 106 235 270
Animas
Durango April-July310 380 425 102 480 545
Florida
Lemon Res, Durango, Nr April-July36 47 55 100 64 75
La Plata
Hesperus April-July16 19 23 100 29 35
Mancos
Mancos, Nr April-July24 30 36 116 43 52

Differences between the full period forecasts and the residual forecasts may not exactly equal the actual observed volumes due to rounding conventions (see Definitions section).

Green End of Month Reservoir Contents (kaf)

EOM
Contents		Percent
EOM
Average		Percent
Usable
Capacity		Last Year
EOM		Last Year
%Average		EOM
Average		Usable
Capacity
untitled Green
Fontenelle Res, Fontenelle Nr 170.0 113 49 233.7 156 150.1 344.8
untitled Big Sandy
Big Sandy Res, Farson, Nr 19.7 119 51 21.5 130 16.6 38.3
Blacks Fork
Meeks Cabin 7.0 60 23 22.5 195 11.5 29.9
untitled Ef Smiths Fork
Stateline Res, Robertson,nr 6.0 107 43 9.5 170 5.6 13.9
untitled Green
Flaming Gorge Res, Flaming Gorge Dam, At 3162.8 104 84 3234.4 106 3050.5 3749.0
untitled Strawberry
Solider Springs,nr 792.4 120 72 837.6 127 659.9 1105.9
Starvation Res, Duchesne, Nr 150.6 109 91 146.7 106 138.8 165.3
untitled Rock Ck
Upper Stillwater Res 11.1 128 35 14.2 164 8.6 31.4
untitled Lake Fork
Moon Lake Res, Mtn Home, Nr -9999.0 -99 -99 30.6 125 24.4 36.5
untitled Big Brush Ck
Red Fleet Res, Vernal, Nr 16.1 89 63 11.3 63 18.0 25.7
untitled Price
Scofield Res, Scofield, Nr 10.9 37 17 12.5 42 29.9 65.8
untitled Seeley Ck
Joes Vly Res, Orangeville, Nr 36.8 94 59 40.7 104 39.3 62.5
untitled Huntington Ck
Electric Lake 17.0 89 54 18.8 98 19.2 31.5
untitled
TOTAL 4400.4 106 78 4634.0 111 4147.9 5663.9


Upper Colorado End of Month Reservoir Contents (kaf)

EOM
Contents		Percent
EOM
Average		Percent
Usable
Capacity		Last Year
EOM		Last Year
%Average		EOM
Average		Usable
Capacity
untitled Colorado
Lake Granby, Granby, Nr 436.9 124 89 496.9 141 352.2 490.3
untitled Willow Ck
Willow Ck Res, Granby, Nr 8.3 104 91 8.9 112 8.0 9.1
untitled Williams Fork
Williams Fork Res, Parshall, Nr 78.0 122 80 78.5 123 63.8 96.9
untitled Muddy Ck
Wolford Mountain Reservoir 42.6 95 65 45.7 102 44.6 66.0
untitled Blue
Dillon Res 236.9 106 93 250.1 112 223.2 254.0
Green Mtn Res 67.9 84 46 75.0 93 81.1 146.9
untitled Homestake Ck
Homestake Res -9999.0 -99 -99 -9999.0 -99 31.9 43.0
untitled Frying Pan
Ruedi Res, Basalt, Nr 70.3 97 69 81.5 113 72.4 102.0
untitled Plateau Ck
Vega Res, Collbran, Nr 12.1 96 37 14.5 115 12.6 32.9
untitled Taylor
Taylor Park Res 69.7 104 66 79.0 118 66.9 106.2
untitled Gunnison
Blue Mesa Res 590.1 115 71 546.7 106 514.6 829.5
Morrow Point Res 109.6 98 94 110.6 99 111.4 117.0
Crystal Res 15.6 102 89 15.0 98 15.3 17.5
untitled Muddy Ck
Paonia Res, Bardine, Nr 1.1 26 6 0.7 18 4.2 16.7
untitled Uncompahgre
Ridgway Res 63.5 92 77 77.0 111 69.2 83.0
untitled Dolores
Mcphee Res 246.3 91 65 183.5 68 270.9 381.1
untitled
TOTAL 2048.8 107 75 2063.5 108 1910.6 2749.1
Colorado
Lake Powell 11426.7 66 47 11146.8 64 17338.2 24322.0
untitled
TOTAL 11426.7 66 47 11146.8 64 17338.2 24322.0


San Juan End of Month Reservoir Contents (kaf)

EOM
Contents		Percent
EOM
Average		Percent
Usable
Capacity		Last Year
EOM		Last Year
%Average		EOM
Average		Usable
Capacity
untitled Los Pinos
Vallecito Res, Bayfield, Nr 85.1 134 68 97.2 153 63.5 125.4
untitled San Juan
Navajo Res, Archuleta, Nr 1396.5 107 82 1090.3 83 1310.4 1696.0
untitled Florida
Lemon Res, Durango, Nr 21.1 101 53 21.8 104 20.9 39.8
untitled
TOTAL 1502.7 108 81 1209.3 87 1394.7 1861.2

Precipitation Maps




Definitions

10% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 10% chance of being exceeded. Previously referred to as "Reasonable Maximum Forecast".

50% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 50% chance of being exceeded. Previously referred to as "Most Probable Forecast".

90% exceedance forecast: Given the current hydrometeorological conditions, i.e current snowpack, soil moisture and streamflow, the volume that has a 90% chance of being exceeded. Previously referred to as "Reasonable Minimum Forecast".

Acre-Foot (af): The volume equal to one acre covered one foot deep (43,560 cubic feet). See kaf below.

Average: The arithmetic mean. The sum of the values divided by the number of values. Values from 1981-2010 are used for this publication.

Categories: Much Above Average=Greater than 130%, Above Average=111-130%, Near Average=90-110%, Below Average=70-89%, Much Below Average=Less than 70%.

CBRFC: Colorado Basin River Forecast Center.

Forecast Period: The period from April 1 through July 31, unless otherwise noted.

kaf: Thousand Acre-Feet. See Acre-Foot above.

Inflow: The volume of water that flows into a reservoir or lake.

Median: The middle value of an ordered set of values. Half of the values are higher and half of the values are lower. When the set contains an even number of values the median is the average of the two middle numbers.

NOAA: National Oceanic and Atomospheric Administration.

NWS: National Weather Service.

Rounding Conventions:
RangeRound to
0-1.990.01
2.0-19.90.1
20-1991.0
200-9995.0
1000+3 significant digits


Streamflow: The volume of water that flows past a specific stream site.

Water Year: The 12-month period, October 1 through September 30. The water year is designated by the calendar year in which it ends. Thus, the year ending September 30, 2008, is called the "2008 water year."


Additional Information

Water supply forecasts take into consideration present hydrometeorological conditions and use average basin temperatures and precipitation for the forecast period. As the forecast season progresses, a greater portion of the future hydrologic and climatic uncertainty becomes known and monthly forecasts become more accurate. For more information on the tools we use, consult Water Supply Forecasting Tools.

Volume forecasts represent adjusted flows; that is, observed flows with upstream water use taken into account. Adjusted flows will closely approximate natural or unimpaired flows. However, not all upstream diversions or impoundments are measured or quantifiable. For specific adjustments used with each forecast point, consult the Guide to Water Supply Forecasting.

The Water Supply Outlook is issued monthly January through May by the Colorado Basin River Forecast Center. It represents a coordinated effort between the National Weather Service, Natural Resources Conservation Service, Bureau of Reclamation, U.S. Geological Survey and local water district managers.

Note: Data used in this report are provisional and are subject to revision.

For more information, or to be included on the mailing list, please contact:

Colorado Basin River Forecast Center
2242 W North Temple
Salt Lake City, UT 84116
(801) 524-5130
www.cbrfc.noaa.gov